Heat Seal Strength Performance of Medical Blister Package

XLW(M) Tensile Tester

A blister package is one type of pre-formed plastic packaging, which has high barrier property andprotects products from external contaminations. Today, blister packaging is widely used for protecting products against external factors, such as humidity and contamination for extended periods of time.Blister packagingusually has a backing of paperboard or a lidding seal of aluminum foil or plastic.

In the medical industry, blister packs are commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges.The medicines are held in the blister cavities, which are independent from each other so even though one blister cavity is broken, others will stay intact. The heat seal strength of the paperboard or aluminum foil should be adequate. Otherwise, when one tablet or capsule is removed from the blister package, the other blister cavities may break and as a result, the medicine may become deteriorated because of entering of air or moisture. Or even worse, the medicine may fall out of the blister cavities. Therefore, it is necessary to test the heat seal strength of the medical blister packageto guarantee the quality of medicines contained inside.

Hereinafter, we take a blister package made of rigid PVCNote sheet and aluminum foil as test specimen to elaborate on how to test the heat seal strength of blister package. We use Labthink’s XLW (M) Auto Tensile Tester as testing instrument.

Note:The common materials used for blister package include PVC, PCTFE and COC.

The heat seal strength tests can be performed according to the following procedures.

Step 1: Seal the rigid PVC sheet and aluminum foil with Labthink HST-H6 Heat Seal Tester under specified conditions (sealing temperature 155±5℃, sealing pressure 0.5MPa, dwell time 1 second).

Step 2: Cut 3 pieces of specimens whose length should be 15mm.

Step 3: Mount the prepared specimen in the sample grips of XLW (M) Auto Tensile Tester. Select test speed 200 mm/min and then start test. When test is finished, the instrument will calculate and record the test results automatically.

According to the test results given by the instrument, the manufacturer can determine whether the blister package can meet their requirements for packing of medicines.

About Labthink Instruments Co., Ltd:

Labthink Instruments Co., Ltd is one leading supplier of packaging testing instruments, which is headquartered in Jinan, China and operated in Boston, U.S.A.